Here at the Eckhardt family orchard in Fredericksburg, Texas—like all orchards—cold is the switch that triggers the growing sequence that by summer has limbs sagging with ripe, juicy peaches. But the reliable chill season in Texas Hill Country that allowed Otto Echhardt to start the family business here in the 1930s is no longer. Warmer winters are hurting the Texas peach crop. But while farmers like the Eckhardts worry about the future, the district’s long-time congressman, Lamar Smith, has worked to block efforts to rein in climate change and even to study it.